#include "pico/stdlib.h"
#include "hardware/adc.h"
#include "hardware/irq.h"
#include "hardware/timer.h"

#define ADC_VOLT_PIN 26
#define ADC_CURR_PIN 27
#define BUTTON_PIN 8
#define DIGIT1 10
#define DIGIT2 11
#define DIGIT3 12
#define SEGMENT_A 0
#define SEGMENT_B 1
#define SEGMENT_C 2
#define SEGMENT_D 3
#define SEGMENT_E 4
#define SEGMENT_F 5
#define SEGMENT_G 6

volatile uint8_t mode = 0;
volatile uint16_t voltage = 0;
volatile uint16_t current = 0;

const uint8_t digit_segments[] = {
    0b00111111, // 0
    0b00000110, // 1
    0b01011011, // 2
    0b01001111, // 3
    0b01100110, // 4
    0b01101101, // 5
    0b01111101, // 6
    0b00000111, // 7
    0b01111111, // 8
    0b01101111  // 9
};

struct repeating_timer timer;

void setup();
void button_callback(uint gpio, uint32_t events);
bool refresh_display(struct repeating_timer *t);
uint16_t read_adc(uint8_t channel);
void display_digit(uint8_t digit, uint8_t position);
void display_clear();
void display_update(uint16_t value);

void setup() {
    stdio_init_all();
    adc_init();
    adc_gpio_init(ADC_VOLT_PIN);
    adc_gpio_init(ADC_CURR_PIN);
    gpio_init(BUTTON_PIN);
    gpio_set_dir(BUTTON_PIN, GPIO_IN);
    gpio_pull_up(BUTTON_PIN);

    for (int i = SEGMENT_A; i <= SEGMENT_G; i++) {
        gpio_init(i);
        gpio_set_dir(i, GPIO_OUT);
    }
    for (int i = DIGIT1; i <= DIGIT3; i++) {
        gpio_init(i);
        gpio_set_dir(i, GPIO_OUT);
    }

    add_repeating_timer_ms(5, refresh_display, NULL, &timer);
    gpio_set_irq_enabled_with_callback(BUTTON_PIN, GPIO_IRQ_EDGE_FALL, true, &button_callback);
}

void button_callback(uint gpio, uint32_t events) {
    mode = !mode;
}

bool refresh_display(struct repeating_timer *t) {
    static uint8_t digit_index = 0;
    uint16_t value = mode == 0 ? voltage : current;
    uint16_t display_value = (value * 3300) / 4096;  // Convert ADC value to millivolts
    uint8_t digits[3] = {display_value / 1000,
     (display_value / 100) % 10, 
     (display_value / 10) % 10};

    display_clear();
    display_digit(digits[digit_index], digit_index);

    digit_index = (digit_index + 1) % 3;
    return true;
}

uint16_t read_adc(uint8_t channel) {
    adc_select_input(channel);
    uint16_t raw = adc_read();
    return (raw * 3300) / 4096; // Convert to millivolts
}

void display_digit(uint8_t digit, uint8_t position) {
    uint8_t segments = digit_segments[digit];
    for (int i = 0; i < 7; i++) {
        gpio_put(SEGMENT_A + i, (segments >> i) & 1);
    }

    gpio_put(DIGIT1 + position, 1);
}

void display_clear() {
    for (int i = SEGMENT_A; i <= SEGMENT_G; i++) {
        gpio_put(i, 0);
    }
    for (int i = DIGIT1; i <= DIGIT3; i++) {
        gpio_put(i, 0);
    }
}

int main() {
    setup();
    while (1) {
        voltage = read_adc(0);
        current = read_adc(1);
        sleep_ms(0.1);
    }
    return 0;
}